We propose to continue to attempt to separate, purify, and identify the several oxidation products formed from benz(a)pyrene and from pyrene and other related polycyclic aromatic hydrocarbons in radiation-induced air oxidations. We shall be applying high-pressure liquid column chromatography, thin-layer chromatography, etc, and a variety of spectral methods for these studies, including mass spectra. Radiation-induced oxidations will be made using either cobalt-60 gamma radiation of 254 nm ultraviolet light, with pure crystalline substrates or substrates adsorbed onto silica gel. All oxidation product mixtures and all resolved pure oxidation products will be evaluated for their putative mutagenicity using test strains of Salmonella typhimurium bacteria. BIBLIOGRAPHIC REFERENCES: "Gamma Radiation Induced Autoxidation and Mutagenic Activation of Benzo (a) pyrene", T.L. Gibson, V.B. Smart, and L.L. Smith, Abstracts of papers, 32nd Southwest Regional Meeting, American Chemical Society, Ft. Worth, Tex., Dec. 1-3, 1976, p. 24. "Nonenzymic Mutagenic Activation of Benzo (a) Pyrene" T.L. Gibson, V.B. Smart, and L.L. Smith, Abstracts of papers, to be presented before the 173rd National Meeting, American Chemical Society, New Orleans, La., Mar. 20-25, 1977. In press.